We exports Extruded Fin Tubes which are manufactured by cold rotary extrusion process. The Extruded Fin is formed from an outer aluminium tube with a large wall thickness, which is aligned over an inner base tube. The two tubes are pushed through three arbors with rotating discs that literally squeeze or extrude the aluminium fins up and out of the muff material in a spiral shape in one operation. The process of extrusion hardens the fins and prevents dissimilar metal contacts at the fin root. The exposed external surface is aluminium and there are no minute gaps between adjacent fins where moisture can penetrate. This ensures good efficiency that is expected when using an extended surface for heat transfer. During the finning process a tight mechanical bond is made between the finned aluminium outer tube and inner base tube of the required metal.